The present invention relates, among other things, to a method in looms or textile machines for the linear measurement and magazine storage of thread, which is fed out in a feed direction over thread support elements situated at an interval from one another, that is to say the bread support elements form a feed path. The invention also relates to an arrangement for the linear measurement and magazine storage of thread ahead of the pick in looms or textile machines and comprising thread feed elements and thread length measuring elements together with magazines designed to store a predetermined quantity of tread (quantity of thread or yarn) ahead of the pick in the machine.
Various types of magazine and feed wheel mechanism constructions are already known in the loom and textile machine sector. The function of the magazine is to store a quantity of thread that is to be used up in a pick or in a thread transfer function in the machine. The respective quantity of thread may be stored according to each pick and there is therefore a requirement that the quantity of thread be correct, for which reason length measuring functions also form part of the known arrangements. General reference is made to the patent literature in connection with this.
In the case of flat thread, for example, there is a need to be able to produce accumulated stocks in the magazine without the risk of the thread twisting or tangling during magazine storage or drawing out. This may also apply to other types of thread, for which reason the present invention addresses itself quite generally to various types of thread, but especially to flat thread, the stated problem of which, among other tings, the new magazine storage and measuring function is intended to solve.
It is also desirable, in associated types of looms and textile machines, to be able to arrange magazine functions so that high pick speeds of 60 picks per minute, for example, are achieved, and so that a number of pickers, for example 6 pickers, can be used in a number of magazines, which altogether can give draw-out times per thread of 6 sec. per thread, for example. If the pick takes 0.6 sec. for example, this gives 5.4 sec./thread, etc. It must be possible to optimize machine lengths, for example machine lengths of 15 meters, bobbin sizes, run times, total times, etc. effectively. The invention is also intended to solve these problems.
The components involved must be tried and tested and yet technically simple components. It must be possible to apply thread tension-measuring functions and use the feedback function so as to give good or outstanding results when weaving or the like. The invention is also intended to solve these problems.
A method according to the invention is therefore essentially characterized in that feed elements and length-measuring elements are activated and that reversing elements for parts of the thread situated between the thread support elements are actuated by means of actuators. Reversed thread runs ale then introduced into the magazine into the introduction position in the magazine by means of the reversing elements and the reversing elements are returned by means of the actuator once the reversed parts of the thread run have reached said introduction positions in the magazine. When returning the reversing elements to their home positions or starting positions, the parts of the thread introduced into the magazine are retained in said introduction positions by means of retaining devices. The magazine is thus loaded and ready for a relevant pick, in which the stored quantity of thread is drawn out against the action of the retaining device, which must therefore have a function which permits said drawing function.
In one embodiment a pulse generator is used in the length-measuring function. The pulse generator emits pulses, which actuate an alternating current motor in the feed element. In one embodiment a motor in the actuator may be controlled in order to instantaneously reverse/draw or introduce the thread parts into the magazine. After a number of pulses, dependent upon the feed length, from the pulse generator, the alternating current motor is then stopped. Speed-controlled, the motor of the actuator is brought to the home positions or starting positions. After drawing out of the measured length of stored thread, the thread tension is read off by means of a load cell. The number of pulses in the pulse generator is adjusted by comparing the registered actual value on the load cell and the set value used when drawing out. The alternating current motor can be acted upon so that it retracts any excess thread following the pick in the textile machine or loom.
An arrangement according to the invention is essentially characterized by a thread supporting track with thread support elements designed to receive thread drawn out in a drawing direction and by elements reversing parts of the thread, which are designed to bring about interaction with parts of the thread between the thread support elements. The reversing elements are furthermore designed, in said interaction, to displace parts of the thread in directions that deviate from the drawing direction into positions in the magazines. The invention is further characterized in that the reversing elements are designed, after the introduction of parts of the thread into the magazines, to return to the stag positions, and that the magazines are designed with devices that retain said parts of the thread in said positions.
In further developments of the idea of the invention, the length-measuring elements comprise a pulse generator arranged or suspended in a load cell and designed to control the thread-measuring element in the form of an alternating current motor by means of its pulses. The actuator actuates the reversing elements and the relevant actuator may thereby comprise a motor, such as an electric motor, for example, which acts upon the reversing element by way of transmission elements, comprising a toothed belt, for example. The actuator can thereby produce coordinated movement or a common movement of all reversing elements. The pulse generator may be adjustable by means of the registered actual value or the set value used. This provides a thread-measuring function, which in itself has an influence on the quantity of yarn. The thread may accordingly take the form of a flat thread and the thread support elements may consist of wheels or rollers, like the reversing elements. In one embodiment the magazines comprise elongate members, which extend in said directions that deviate from said feed direction. Said members may in principle be stirrup-shaped, the openings of the stirrups extending in the feed direction. Reversing elements are displaceably arranged along the (outer) edges of the members. Displacement into the positions in the magazine is designed to occur with the thread or the parts of the thread lying between the reversing elements and said member edges. Said devices may comprise brush or burr-like elements or devices which have a retaining function when the reversing elements return to the original or starting positions, but a yielding function when drawing out the thread from the magazine. The feed element can also be designed to retract any excess part of the thread after the pick. The quantity of thread stored by the magazine can thus be determined by means of the lengths of the thread parts drawn down into the magazine. For example, by selecting different magazine positions it is possible to store different quantities of thread in the magazine. These proposed means permit the use of advantageous dimensions for the bobbin which can be designed, for example, with a weight of 10 kg, an outside diameter of approx. 350 mm, an inside diameter of approx. 180 mm, and a length of approx. 250 mm. A conventional pulse generator and a conventional load cell can be used. Likewise conventional wheel or roller functions may be incorporated and in a preferred embodiment the reversing wheels or the reversing rollers can be coupled to toothed belts or drive motors for this purpose. The magazines may consist of a desired number of elements. The bobbin can be driven by a conventional alternating current motor and the pulse generator may be of the type that measures the length and adjusts the bobbin motor in a manner known in the art. The function is advantageous in that the bobbin motor winds out the weft thread and the motor that acts upon the reversing elements instantaneously draws in order to fill up the magazine. When the pulse generator has measured the predetermined length, the feed motor is stopped and the motor that controls the reversing elements can return, speed-controlled, to the home position. The weft thread can easily be retained when the reversing elements are returning, but at the same time allows the thread to be drawn out of the magazine. The load cell can be read off when the magazine is emptied of stored thread the actual value being compared with the set value and the difference adjusted by more or fewer pulses for the next weft. The thread tension can thereby be measured on a current pick and measured at 200 grams, for example. If a reduced thread tension is required, for example 150 grams, the thread length is increased by means of the load cell and pulse generator functions, so that a longer thread is obtained on the next pick (that is to say the arrangement introduces more thread into the magazine). If the thread length on the first pick is worked out to be 2 meters, for example, the thread length on the subsequent pick can be set, for example, to 12 meters and 5 centimeters, and so on. Corresponding functions exist where increased thread tension or reduced thread length are required.